Magnets are employed in a variety of appliances where the application often dictates the physical shape of the magnet and the pattern of magnetization. For example, the rotor of a DC motor incorporates a magnet in the shape of a hollow cylinder where the magnetization is generally radial, that is, perpendicular to the cylindrical walls. Although it is possible to construct various magnet shapes from several standard sized and shaped magnets, it is often preferable to achieve the desired magnetization with a single object having the desired shape.
During magnetization, an object to be permanently magnetized is placed in a region having a magnetic field with a particular configuration. To that end, such a magnetic field often is generated with a magnetizing system. One type of magnetizing system includes a magnetizer that supplies electrical current to a coupled magnetizing fixture. The fixture typically has an electrically conductive, non-permanently magnetizeable core of substantial magnetic permeablilty to concentrate and focus the magnetic fields produced by current flowing through a plurality of surrounding conductors. To begin magnetization, magnetizeable material to be permanently magnetized, e.g., steel, may be placed around or about the magnetizing fixture. The magnetizing system then generates a magnetic field to magnetize the material.
Proper configuration of the magnetic fields requires that electrical current flow only through the electrical conductors. Undesirably, because of contact between the conductors and the core, current often is diverted into the steel core. Current flowing through the core thus distorts both the resulting magnetic fields and, consequently, the subsequent permanent magnetization of the object being magnetized.